With rapid popularization of communications networks, a Wireless Fidelity (Wi-Fi for short) technology is increasingly popular among people, and becomes a function that is essentially configured in a communications device.
Even though the Wi-Fi technology brings much convenience to users, because the Wi-Fi technology does not have a power control technology similar to that of a 2G/3G network, there is a large power consumption problem, which affects use of intelligent terminals. In an existing communications device, a Wi-Fi function needs to be implemented by using the following components, as shown in FIG. 1: a Wi-Fi chip, a power amplifier (PA for short), a filter, and an antenna. The Wi-Fi chip sets the PA to be enabled (a signal PA_EN is enabled), and sends, to the PA, a service request signal carrying data to be sent. The PA amplifies the service request signal within an enabled period, and sends the service request signal to the filter. After performing filtering processing on the amplified service request signal, the filter sends the service request signal to an external communications device by using the antenna.
To meet a requirement of sending a high rate (for example, a modulation scheme is 256QAM or 64QAM) signal imposed on linearity property, in the prior art, the Wi-Fi chip sets a static bias point of the PA relatively high; otherwise, a sent signal is intercepted and distorted. In addition, the Wi-Fi chip sets same static bias points for the PA according to different sending rates, so that the static bias points are managed together.
However, a solution for implementing the Wi-Fi function in the prior art also has the following disadvantages. The Wi-Fi chip sets uniform static bias points for the PA according to different sending rates; therefore, when a sending rate is high, power consumption of the PA is relatively high, and when the sending rate is low, the power consumption of the PA is also in a relatively high state, resulting in that the power consumption of the PA is always in a relatively high state and cannot be reduced. In addition, because the power consumption of the PA is always in a relatively high state, a battery in the communications device needs to continuously supply power to the Wi-Fi chip and the PA, consuming excessively much electricity of the battery.